Nous présentons une réalisation purement fonctionnelle et paresseuse de la technique du mode inverse de différentiation algorithmique. Cette technique, qui permet de calculer de manière précise et efficace les dérivées des expressions numériques dans un programme, est devenue indispensable dans plusieurs branches de programmation scientifique. Le mode inverse ou adjoint demande souvent l’usage ...

Data warehouses collect and maintain large amounts of data from several distributed and heterogeneous data sources. Because of security reasons, operational requirements, and technical feasibility it is often impossible for data warehouses to access the data sources directly. Instead data warehouses have to replicate legacy information as detail data in order to be able to maintain their summar...

the vapor extraction (vapex) process, a solvent-based enhanced oil recovery process has been found promising for some heavy oil reservoirs. in this work, the vapex process is studied using a compositional simulator on a number of single-block and multiple block fractured systems. pvt data of one of an iranian heavy oil reservoir are used to tune the equation of state. effects of fracture spacin...

Developments in computer-mediated communications are not only providing new opportunities for educators but also changing roles and competencies in learning and teaching environments. Experts agree that teaching online requires different roles and competencies. The literature includes several studies on roles and competencies for online teaching. However, as Le Boterf underlines, roles and comp...

spatial planning system of a country is the array of its planning systems. getting familiar with spatial planning system of different countries and their experiences could help for comparison and accommodation so that making decision and defining appropriate planning system could be done. this article has studied the spatial planning system of portugal and since there are different factors affe...

The adaptation of the BitTorrent protocol to multimedia on-demand streaming systems essentially lies on the modification of its two core algorithms, namely the piece and the peer selection policies, respectively. Much more attention has though been given to the piece selection policy. Within this context, this article proposes three novel peer selection policies for the design of BitTorrent-lik...